[Prostacyclin production in internal mammary ano radial arteries and saphenous veins of diabetic and non diabetic subjects].
BACKGROUND
Myocardial revascularization surgery has used several vessels as coronary grafts including internal mammary and radial arteries which have a better prognosis than saphenous vein. Their long-term patency has been associated with the release of endothelium vasodilator and anti-aggregating products such as prostacyclin. Diabetes induces endothelial dysfunction and a high number of diabetics require revascularization.


OBJECTIVE
To assess the capacity to synthesize prostacyclin of different vessels from diabetics.


METHODS
Internal mammary and radial arteries and saphenous veins obtained from 10 diabetic and 10 non diabetic patients subjected to coronary artery bypass surgery were studied. The capacity to synthesize prostacyclin was assessed in these vessels measuring its hydrolysis product, the 6-keto-PGFla by radioimmunoassay.


RESULTS
Internal mammary arteries and saphenous veins from diabetics synthesized a lower amount of prostacyclin than those from non-diabetics. The radial artery produced similar amounts of prostacyclin in both groups. This response was associated with an increase of the conversion of the precursor arachidonic acid to prostacyclin. The saturating concentrations of this acid required to achieve the maximal stimulation were higher in the radial artery (20 microM) than in the internal mammary artery and saphenous vein (10 microM), suggesting that the enzymatic activity of the radial artery was not affected by diabetes.


CONCLUSIONS
The radial artery appears as the best replacement vessel for coronary surgery in diabetics. Its favorable biochemical profile and potential lower long-term occlusion rate may be relevant for a better prognosis of myocardial revascularization in these patients.
Guivernau
Mauricio
M
Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile. mguivern@med.uchile.cl
Berr
Miguel
M
D016718:Arachidonic Acid / Q000494:pharmacology; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000601:surgery; D048909:Diabetes Complications; D004730:Endothelium, Vascular / Q000378:metabolism; D011464:Epoprostenol / Q000096:biosynthesis*; D006083:Graft Occlusion, Vascular / Q000503:physiopathology; D006801:Humans; D008323:Mammary Arteries / Q000378:metabolism* / Q000637:transplantation; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism; D011379:Prognosis; D017534:Radial Artery / Q000378:metabolism* / Q000637:transplantation; D012501:Saphenous Vein / Q000378:metabolism*; D014661:Vasoconstriction / Q000502:physiology; D014664:Vasodilation / Q000502:physiology
D016718:Arachidonic Acid; D009569:Nitric Oxide; D011464:Epoprostenol